Abstract:

An organic polyurethane shape memory material and a preparation method
thereof are disclosed. The organic polyurethane shape memory material
includes a C10 chain or C18 chain and it consists of hard segment and
soft segment. The preparation method thereof includes the steps of:
The single-chain type dendrimer reacts with diethylenetriamine to produce
multiple chains type dendrimer. And then at least one type dendrimer
reacts with N-(3-aminopropyl)diethanolamine to produce at least one type
dendritic diols. Next polymer
HO(C6H10O2)xC2H4OC2H4(C6H.su-
b.10O2)yOH, x+y=25˜26 reacts with methylenedi-p-phenyl
diisocyanate and then at least one type dendritic diols is added to react
so as to get organic polyurethane shape memory material. The material of
the present invention overcomes shortcoming of metal alloy and ceramic
such as poor processability, difficulty in modification and high cost.
Moreover, it also increase mechanical properties of polymer.

Claims:

1. An organic polyurethane shape memory material comprising: ##STR00012##
wherein R1 is CnH2n and n is from 8 to 15;R2 is
(C6H10O2)xC2H4OC2H4(C6H10O2)y and x+y=25.about.26; andR3 is selected from the group
consisting of: ##STR00013## ##STR00014## ##STR00015##

3. A preparation method of the organic polyurethane shape memory material
comprising the steps of:dissolving methylenedi-p-phenyl diisocyanate and
isobutyryl chloride in xylene, reacting with each other to get a first
solution; filtering the first solution and purifying filtrate by
recrystallization to produce
4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl methane;
reacting the 4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl
methane with primary alcohol to produce single-chain type dendrimer while
the primary alcohol is selected from a group of decyl alcohol and stearyl
alcohol and the dendrimer is single-chain type dendrimer having a decyl
group or single-chain type dendrimer having an octadecyl group;reacting
the single-chain type dendrimer with diethylenetriamine to produce
multiple chains type dendrimer that is multiple chains type dendrimer
having a decyl group or multiple chains type dendrimer having an
octadecyl group;reacting at least one type dendrimer with
N-(3-aminopropyl)diethanolamine to produce at least one type dendritic
diols that is dendritic diols having a decyl group or dendritic diols
having an octadecyl group; andreacting
HO(C6H10O2)xC2H4OC2H4(C6H.su-
b.10O2)yOH, x+y=25.about.26 polymer with methylenedi-p-phenyl
diisocyanate and then adding at least one type dendritic diols to react
so as to get organic polyurethane shape memory material.

4. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein the step of dissolving
methylenedi-p-phenyl diisocyanate and isobutyryl chloride in xylene,
reacting with each other to produce a first solution further comprising a
step of: adding triethylamine to catalyze reaction of producing the first
solution by dissolving the methylenedi-p-phenyl diisocyanate and the
isobutyryl chloride in xylene.

5. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein reaction temperature of the step
of dissolving methylenedi-p-phenyl diisocyanate and isobutyryl chloride
in xylene, reacting with each other to produce a first solution is from
110.degree. C. to 130.degree. C.

6. The preparation method of the organic polyurethane shape memory
material as claimed in claim 5, wherein the reaction temperature of the
step of dissolving methylenedi-p-phenyl diisocyanate and isobutyryl
chloride in xylene, reacting with each other to produce a first solution
is 120.degree. C.

7. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein the step of filtering the first
solution and purifying filtrate by recrystallization to produce
4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl methane further
comprising a step of: using cyclohexane in recrystallization for
purifying the filtrate.

8. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein the step of reacting the
4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl methane with
primary alcohol to produce single-chain type dendrimer further comprising
a step of: dissolving
4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl methane in
tetrahydrofuran.

9. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein reaction time of the step of
reacting the 4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl
methane with primary alcohol to produce single-chain type dendrimer is
from 3 to 5 hours.

10. The preparation method of the organic polyurethane shape memory
material as claimed in claim 9, wherein the reaction time of the step of
reacting the 4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl
methane with primary alcohol to produce single-chain type dendrimer is 4
hours.

11. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein reaction temperature of the step
of reacting the 4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl
methane with primary alcohol to produce single-chain type dendrimer is
from 70.degree. C. to 90.degree. C.

12. The preparation method of the organic polyurethane shape memory
material as claimed in claim 11, wherein the reaction temperature of the
step of reacting the
4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl methane with
primary alcohol to produce single-chain type dendrimer is 80.degree. C.

13. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein in the step of reacting the
4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl methane with
primary alcohol to produce single-chain type dendrimer, equivalence ratio
of the 4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl methane
to the primary alcohol is 1:1.

14. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein in the step of reacting the
single-chain type dendrimer with diethylenetriamine to produce multiple
chains type dendrimer, the dendrimer reacts with diethylenetriamine in
tetrahydrofuran.

15. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein in the step of reacting the
single-chain type dendrimer with diethylenetriamine to produce multiple
chains type dendrimer, reaction temperature is from 50.degree. C. to
70.degree. C.

16. The preparation method of the organic polyurethane shape memory
material as claimed in claim 15, wherein in the step of reacting the
single-chain type dendrimer with diethylenetriamine to produce multiple
chains type dendrimer, the reaction temperature is 60.degree. C.

17. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein after the step of reacting the
single-chain type dendrimer with diethylenetriamine to produce multiple
chains type dendrimer, the method further comprising a step of: reacting
the multiple chains type dendrimer with
4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl methane to
produce another multiple chains type dendrimer.

18. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein reaction time of the step of
reacting at least one type dendrimer with N-(3-aminopropyl)diethanolamine
to produce at least one type dendritic diols is 3 to 5 hours.

19. The preparation method of the organic polyurethane shape memory
material as claimed in claim 18, wherein the reaction time of the step of
reacting at least one type dendrimer with N-(3-aminopropyl)diethanolamine
to produce at least one type dendritic diols is 4 hours.

20. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein reaction temperature of the step
of reacting at least one type dendrimer with
N-(3-aminopropyl)diethanolamine to produce at least one type dendritic
diols is 70.degree. C. to 90.degree. C.

21. The preparation method of the organic polyurethane shape memory
material as claimed in claim 20, wherein the reaction temperature of the
step of reacting at least one type dendrimer with
N-(3-aminopropyl)diethanolamine to produce at least one type dendritic
diols is 80.degree. C.

22. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein in the step of reacting at least
one type dendrimer with N-(3-aminopropyl)diethanolamine to produce at
least one type dendritic diols, equivalence ratio of the one type
dendrimer to the N-(3-aminopropyl)diethanolamine is 1:1.

23. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein the step of reacting
HO(C6H10O2)xC2H4OC2H4(C6H.su-
b.10O2)yOH, x+y=25.about.26 polymer with methylenedi-p-phenyl
diisocyanate and then adding at least one type dendritic diols to react
so as to get organic polyurethane shape memory material further
comprising a step of: dissolving the
HO(C6H10O2)xC2H4OC2H4(C6H.su-
b.10O2)yOH, x+y=25.about.26 polymer in toluene and control
temperature at 60.degree. C. to 70.degree. C.

24. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein in the step of reacting
HO(C6H10O2)xC2H4OC2H4(C6H.su-
b.10O2)yOH, x+y=25.about.26 polymer with methylenedi-p-phenyl
diisocyanate and then adding at least one type dendritic diols to react
so as to get organic polyurethane shape memory material, reaction time of
the HO(C6H10O2)xC2H4OC2H4(C6-
H10O2)yOH, x+y=25.about.26 polymer with the
methylenedi-p-phenyl diisocyanate is 0.5 hour.

25. The preparation method of the organic polyurethane shape memory
material as claimed in claim 3, wherein in the step of reacting
HO(C6H10O2)xC2H4OC2H4(C6H.su-
b.10O2)yOH, x+y=25.about.26 polymer with methylenedi-p-phenyl
diisocyanate and then adding at least one type dendritic diols to react
so as to get organic polyurethane shape memory material, reaction time of
the added one type dendritic diols is 3 to 4 hours.

Description:

BACKGROUND OF THE INVENTION

[0001]The present invention relates to a shape memory organic material and
a preparation method thereof, especially to an organic polyurethane shape
memory material and a preparation method thereof that are applied to
materials with shape recovery property.

[0002]Smart material is a novel functional function that senses external
stimuli. Self-judges and take actions and such material has been studied
extensively with great application potential. They may be used in daily
lives, information technology and even national defense industry.
Generally, smart materials have following features:

[0006]The most common smart material is shape-memory material that is
divided into three categories.

[0007](1) Metal Alloy:

[0008]In 1963, Buechler etc. described Shape-memory feature of the
nickel-titanium alloy by phase transition of materials under different
temperature. Due to its biocompatibility, such material is extensively
applied to surgery device and implant.

[0009](2) Ceramic:

[0010]Wei etc. disclosed ceramic material such as ZrO2. Like metal alloy,
the ceramic material is applied with temperature variations or stress so
as to make material structure phase transition occur.

[0011](3) Polymer:

[0012]There are classified into two types chemical cross-linking and
physical cross-linking. Earlier in 1960, Polyethylene (PE) molecules are
joined by covalent cross-linking so as to be heat shrink tubing for
covering wires. The deformation is triggered by melting temperature of
the PE while covalent cross-linking fixes the deformation. As to
poly(vinyl chloride) (PVC), high cross-linking is obtained by heating and
the material is also shape-memory material. In physical cross-linking
system such as gel, the volume and swelling of polymer are changed by PH
vale, dissolvent and sensitivity to ionic strength. But it's main
shortcoming is poor mechanical strength.

[0013]However, metal and ceramic material both have disadvantages of high
cost, poor processability and difficulty in modification. As to the
polymer gel system, the mechanical strength is poor. Thus there is a need
to provide a new organic polyurethane shape memory material that has
advantages of low cost, good processability and easy modification.
Moreover, the mechanical strength is also improved.

SUMMARY OF THE INVENTION

[0014]Therefore it is a primary object of the present invention to provide
an organic polyurethane shape memory material and a preparation method
thereof that avoid poor processability of metal alloy and ceramic
material.

[0015]It is another object of the present invention to provide an organic
polyurethane shape memory material and a preparation method thereof that
improve difficulty in modification of metal alloy and ceramic material.

[0016]It is a further object of the present invention to provide an
organic polyurethane shape memory material and a preparation method
thereof that overcome shortcoming of high manufacturing cost of metal
alloy and ceramic material.

[0017]It is a further object of the present invention to provide an
organic polyurethane shape memory material and a preparation method
thereof that avoid poor mechanical strength of polymer gel system.

[0018]In order to achieve objects, the organic polyurethane shape memory
material according to the present invention includes:

##STR00001##

[0019]wherein R1 is CnH2n and n has a value of from 8 to 15, the preferred
R1 is C13H26;

[0022]A preparation method of the organic polyurethane shape memory
material is composed of following steps: dissolve methylenedi-p-phenyl
diisocyanate and isobutyryl chloride in xylene, reacting with each other
to get a first solution. Filter the first solution and the filtrate is
purified by recrystallization to produce
4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl methane (MIA).
The 4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl methane
reacts with primary alcohol to produce dendrimer with single chain
structure while the primary alcohol is selected from a group of decyl
alcohol and stearyl alcohol and the dendrimer is single-chain type
dendrimer having a decyl group or single-chain type dendrimer having an
octadecyl group. The single-chain type dendrimer reacts with
diethylenetriamine to produce multiple chains type dendrimer that is
multiple chains type dendrimer having a decyl group or multiple chains
type dendrimer having an octadecyl group. At least one type dendrimer
reacts with N-(3-aminopropyl)diethanolamine to produce at least one type
dendritic diols that is dendritic diols having a decyl group or dendritic
diols having an octadecyl group. Polymer
HO(C6H10O2)xC2H4OC2H4(C6H.su-
b.10O2)yOH, x+y=25˜26 reacts with methylenedi-p-phenyl
diisocyanate (MDI) and then at least one type dendritic diols is added to
react so as to get organic polyurethane shape memory material.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023]The structure and the technical means adopted by the present
invention to achieve the above and other objects can be best understood
by referring to the following detailed description of the preferred
embodiments and the accompanying drawings, wherein

[0024]FIG. 1 is a flow chart showing a preparation method of an organic
polyurethane shape memory material according to the present invention;

[0025]FIG. 2 is a schematic drawing showing synthesis of
4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl methane
according to the present invention;

[0026]FIG. 3 is a schematic drawing showing synthesis of dendrimer with
C10 chain according to the present invention;

[0027]FIG. 4 is a schematic drawing showing synthesis of dendrimer with
C18 chain according to the present invention;

[0028]FIG. 5 is a schematic drawing showing synthesis of dendritic diol
with C10 chain according to the present invention;

[0029]FIG. 6 is a schematic drawing showing synthesis of dendritic diol
with C18 chain according to the present invention;

[0059]wherein R1 is CnH2n and n has a value of from 8 to 15, the preferred
R1 is C13H26; [0060]R2 is
(C6H10O2)xC2H4OC2H4(C6H10O2)y and x+y=25˜26; and [0061]R3 is selected from one of
the followings:

##STR00009## ##STR00010## ##STR00011##

[0062]A preparation method of the organic polyurethane shape memory
material consists of following steps, as shown in FIG. 1:

[0063]S1 dissolve methylenedi-p-phenyl diisocyanate and isobutyryl
chloride in xylene, reacting with each other to get a first solution;

[0064]S2 filter the first solution and the filtrate is purified by
recrystallization to produce
4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl methane (MIA);

[0065]S3 the 4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl
methane reacts with primary alcohol to produce dendrimer with single
chain structure while the primary alcohol is selected from a group of
decyl alcohol and stearyl alcohol and the dendrimer is single-chain type
dendrimer having a decyl group or single-chain type dendrimer having an
octadecyl group;

[0066]S4 the single-chain type dendrimer reacts with diethylenetriamine to
produce multiple chains type dendrimer that is multiple chains type
dendrimer having a decyl group or multiple chains type dendrimer having
an octadecyl group;

[0067]S5 at least one type dendrimer reacts with
N-(3-aminopropyl)diethanolamine to produce at least one type dendritic
diols that is dendritic diols having a decyl group or dendritic diols
having an octadecyl group; and

[0068]S6 HO(C6H10O2)xC2H4OC2H4(C.s-
ub.6H10O2)yOH, x+y=25˜26 polymer reacts with
methylenedi-p-phenyl diisocyanate (MDI) and then at least one type
dendritic diols is added to react so as to get organic polyurethane shape
memory material.

[0069]In the step S1, triethylamine is used to catalyze the reaction of
generating the first solution by dissolving the methylenedi-p-phenyl
diisocyanate and the isobutyryl chloride in xylene. The reaction
temperature of step S1 ranges from 110˜130° C. and
120° C. is preferable. In the step S2, cyclohexane is used in
recrystallization and purification of the filtrate. The step S3 further
includes a step of dissolving
4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl methane in
tetrahydrofuran while the reaction time of the step S3 is from 3 to 5
hours (4 hours is preferable) the reaction temperature is
70˜90° C. and 80° C. is preferred. In the step S4,
the dendrimer and diethylenetriamine react in tetrahydrofuran under
temperature ranging from 50˜70° C. while 60° C. is
preferred After the step S4, a further step is to react the multiple
chains type dendrimer with
4-isocyanate-4-(3,3-dimethyl-2,4-dioxo-azetidine)diphenyl methane to
produce another multiple chains type dendrimer. The reaction time of the
step S5 is 3 to 5 hours while 4 hours is preferable and the reaction
temperature is 70˜90° C., 80° C. is preferred. In the
step S6, the polymer
HO(C6H10O2)xC2H4OC2H4(C6H.su-
b.10O2)yOH, x+y=25˜26 is dissolved in the toluene at
temperature of 60˜70° C. The polymer reacts with
methylenedi-p-phenyl diisocyanate for 0.5 hour and then adding dendritic
diol, continuingly reacting for 3-4 hours.

[0072]Dissolve the methylenedi-p-phenyl diisocyanate (MDI) and the
isobutyryl chloride in the xylene while equivalence ratio of
MDI/isobutyryl chloride is 1:0.7. Heat the solution up to 120° C.,
add triethylamine as catalyst, stir the solution for 3-4 hours. The
solution is cooled to 0° and the first solution (orange liquid) is
produced. After filtering , the filtrate is purified and recrystallized
by cyclohexane to get MIA. The flow chart of the reaction is shown in
FIG. 2.

[0073](2) Synthesis of Various Endrimer

[0074]Dissolve MIA in the tetrahydrofuran (THF) and then add decyl alcohol
or stearyl alcohol into the solution while equivalence ratio of MIA to
one the alcohol is 1:1. After reacting at 80° C. for 4 hours,
remove the THF and add cyclohexane for purification to generate 0.5G (G
represents different generations) dendrimer (single-chain type). The 0.5G
dendrimer reacts with diethylenetriamine in THF, being heated at
60° C. for 3-4 hours. After purification, 1G C10 or C18
dendrimer (multiple-chains type) is produced. Next, the 1G C10 or
C18 dendrimer reacts with MIA in THF to produce 1.5G C10 or
C18 dendrimer (multiple-chains type). Furthermore, 1.5G C10 or
C18 dendrimer reacts with diethylenetriamine in THF solvent, being
heated for 3-4 hours. After purification, 2G C10 or
C18dendrimer is obtained. Repeat the same procedures, 2.5G C10
or C18 dendrimer and 3G C10 or C18 dendrimer are
generated. Refer to FIG. 3, reaction flow of C10 dendrimer is
disclosed and reaction flow of C18 dendrimer is in FIG. 4.

[0078]Firstly, dissolve Tone Polyol
0260(HO(C6H10O2)xC2H4OC2H4(C6H10O2)yOH, x+y=25˜26 (molecular weight 3000) in
toluene and control the temperature of the solution at 65° C. Then
add MDI and catalyst T-12 (Dibutyltin dilaurate) into the solution,
reacting for 0.5 hour. Then add chain extender Di(ethylene glycol) (DEG,
O(CH2CH2OH)2) and react for 3.5 hours. The final product is set into an
oven to form a membrane. The flow chart is shown in FIG. 7.

[0080]Firstly, dissolveTone Polyol 0260 in toluene and control the
temperature of the solution at 65° C. Then add MDI and catalyst
T-12 into the solution, reacting for 0.5 hour. Respectively add two
series chain extender in different generations (0.5G dendritic diol, 1.5G
dendritic diol, 2.5G dendritic diol), reacting for 3.5 hours so as to
produce C10 and C18 side chain dendritic polyurethane that is shape
memory material of the present invention, as shown in FIG. 8. Then the
product is set into the oven at 60° C. for 24 hours to form
membranes.

[0081]Samples of various linear polyurethane and side chain dendritic
polyurethane are shown in list one, wherein L is DEG, D0 represents 0.5G
dendritic diol, D1 represents 1.5G dendritic diol and D2 is 2.5G
dendritic diol (G represents different generations) while a is C10 series
and b is C18 series.

[0083]Taking C10 dendrimer as an embodiment, in production of 0.5G
dendrimer, MIA and 1-decanol with equivalence ratio of 1 are dissolved in
THF, reacting at 80° C. for 4 hours. The yield of addition
reaction is 95% and is monitored by Fourier Transform Infrared
spectrometry (FTIR). As shown in FIG. 9, a characteristic absorption peak
(N═C═O) disappears at 2260 cm-1 while another peak (C═O
of urethane) is generated at 1700 cm-1. By 1H NMR (Proton
Nuclear Magnetic Resonance Spectroscopy) analysis., the chemical shift
(ppm) of the compounds are as following: 3.30 (4H, m, CH2(N)), 3.86 (4H,
s, Ar--CH2-Ar) and 4.02 (4H, t, CH2). Next, IG product is prepared by a
ring-opening addition reaction at 60° C. and the reaction yield is
95%. The reaction is also monitored by FTIR and the characteristic
absorption peak disappears at 1738 cm-1 and 1856 cm-1 (C═O
of azetidine-2,4-dione), as shown in FIG. 10 while another peak (C═O
of malonamide)is generated at 1675 cm-1. The 1H NMR
spectroscopy shows the chemical shift (ppm) of the compounds are 3.30
(4H, m, CH2(N)), 3.94 (4H, s, Ar--CH2-Ar) and 4.02 (4H, t, CH2).
Then the same methods are applied to analyze and identify the products.

[0087]Taking Dendritic diol with C10 chain as an example, in synthesis of
0.5G dendrimer diol, 0.5G dendrimer and N-(3-aminopropyl)diethanolamine
with equivalence ratio of 1:1 are dissolved in THF, reacting at
80° C. for 4 hours. The solution is purified by column
chromatography and thin layer chromatography with elution buffer of Ethyl
Acetate and Acetone. The yield of this ring-opening addition reaction is
95% and is monitored by Fourier Transform Infrared spectrometry (FTIR).
As shown in FIG. 11, the characteristic absorption peak 1(C═O of
azetidine-2,4-dione) disappears at 1738 and 1856 cm-1 while other
peaks (C═O of malonamide) (--OH) are respectively generated at 1675
and 3450 cm-1. Refer to FIG. 12, chemical structure of the compound
is identified by 1H NMR and Fab MS=641 m/z (M.sup.+). After ring
opening of azetidine-2,4-dione, the chemical shift of (4H, s, Ar--CH2-Ar)
moves from 3.94 to 3.86 ppm. Then the same methods are applied to analyze
and identify the products.

[0088]Dendritic Diol with C18 Chain

[0089]Refer to FIG. 13A, chemical structure of 0.5G Dendritic diol is
identified by 1H NMR shown in FIG. 13A, Fab MS=753 m/z (M.sup.+)
shown in FIG. 13B, and differential scanning calorimetry (DSC) shown in
FIG. 14. After ring opening of azetidine-2,4-dione, the chemical shift of
(4H, s, Ar--CH2-Ar) moves from 3.94 to 3.86 ppm. Next the same methods
are applied to analyze and identify the products. Morevoer, by DSC, it is
observed that melting point (Tm) of the 0.5G Dendritic diol is
110° C.

[0090]During synthesis processes of 1.5G Dendritic diol, 1.5G dendrimer
and N-(3-aminopropyl)diethanolamine with equivalence ratio of 1 are
dissolved in THF, reacting at 80° C. for 4 hours. The solution is
purified by the same method as the 0.5G Dendritic diol. The yield of this
ring-opening addition reaction is 65% and is also monitored by Fourier
Transform Infrared spectrometry as the 0.5G Dendritic diol. Refer to FIG.
15, 1H NMR analysis of the 1.5G Dendritic diol is disclosed while
analysis result of Fab MS=1767 m/z (M.sup.+) is shown in FIG. 15B.

[0091]In synthesis of 2.5G Dendritic diol, 2.5G dendrimer and
N-(3-aminopropyl)diethanolamine with equivalence ratio of 1:1 are
dissolved in THF, reacting at 80° C. for 4 hours. The solution is
purified by the same method as the 0.5G Dendritic diol. The yield of this
ring-opening addition reaction is 65% and is also monitored by Fourier
Transform Infrared spectrometry as the 0.5G Dendritic diol. Refer to FIG.
16A, Fourier Transform Infrared spectrometry spectrum is shown and NMR
spectrum is in FIG. 16B.

[0092](3) Polyurethane Series

[0093]Tone Polyol 0260 is dissolved in tolene that is separated with
water, add MDI and T-12 into the solution, reacting at 65° C. and
monitored by FTIR. Refer to FIG. 17A & FIG. 17B, the characteristic
absorption peak of OH group OF Polyol at 3556 cm-1 disappears after
0.5 hour/Then immediately add into chain extender DEG or Dendritic diol.
After 3.5 hours, it is observed peak at 2260 cm-1 (N═C═O)
disappears and it is judged that the reaction is over. Then the product
is set in the oven at 60° C. for 24 hours to form membranes.

[0094]Refer to FIG., 18, in a Fourier transform attenuated total
reflection infrared spectrometry (ATR-FTIR), the presence of
characteristic absorption peak at 3325 cm-1 for the NH group in
urea, amide and urethane is found obviously. The characteristic
absorption peak for CH2 group is present at 2950, 2920 and 2850
cm-1. Moreover, the characteristic absorption peak for C═O group
also form at 1730, 1705, and 1654 cm-1, peaks at 1730 and 1705
cm-1 are contributed by urethane while peak at 1654 cm-1 is
contributed by malonamide and urea. Take c18 chain with 45% hard segment,
it is found that in the dendrimer system (D0 and D1), the characteristic
absorption peak of urethane is separated and present at 1730 and 1705
cm-1 due to multi-hydrogen-bonds of malonamide and urea at 1650
cm-1. It is learned from literature that this phenomenon is caused
by material with microscopic phase separation. Because malonamide has
strong hydrogen bonding, dendrimer is introduced into polyurethane so as
to increase molecular interaction for increasing mechanical properties.
By the strong hydrogen bonding and long carbon chain, Van der Walls'
Force is formed so as to induce formation of hard domain. Thus soft
segment and hard segment in polyurethane are separated and memory as well
as recovery effect of the shape memory material is enhanced.

[0095]Thermal properties of polyurethane are discussed through DSC. The
temperature is increased 10° C. per minute while temperature
decreasing is 20° C. per minute. Compared L-series with C10
series, refer to FIG. 19A & FIG. 19B, it is observed that glass
transition temperature (Tg) of the soft segment of L-series is all the
same -47° C. and this value is not changed along with change of
hard segment amount. Moreover, the melting point (Tm) of the soft segment
is 42° C. The heat of fusion (quadratureHm) and heat of
crystallization (quadratureHc) are decreased along with increasing of
the hard segment amount thus it is known that crystallinity of soft
segment is destructed by introduction of hard segment. Therefore, a
certain degree phase separation exists due to interactions between soft
segments and hard segments. However, influence of the hard segment is not
obvious here. As to D0 series, along with increasing of the hard segment
amount, glass transition temperature (Tg) of the soft segment increases
from -52° C. to -43° C. while the melting point (Tm) of the
soft segment is decreased from 44° C. to 40° C. At the same
time, The heat of fusion and heat of crystallization are both reduced.
However, glass transition temperature (Tg) of the hard segment of above
two series is not obvious.

[0096]Compared L-series with C18 series, refer to FIG. 20A, FIG. 20B and
FIG. 20C, it is observed that glass transition temperature (Tg) of the
soft segment of L-series is all the same -50° C. and this value is
not changed along with change of hard segment amount. Moreover, the
melting point (Tm) of the soft segment is 40° C. while the heat of
fusion (quadratureHm) and heat of crystallization (quadratureHc) are
decreased along with increasing of the hard segment amount thus it is
known that crystallinity of soft segment is destructed by introduction of
hard segment. Therefore, a certain degree phase separation exists due to
interactions between soft segments and hard segments. Compare with C10
series, the melting point of the hard segment is shown at 160° C.
and is increased along with increasing of hard segment. The heat of
fusion is also increased. Thus means influence of the hard segment is
getting increased. As to D0 series, along with increasing of the hard
segment amount, glass transition temperature (Tg) of the soft segment
increases from -39° C. to -26° C. This means the
introduction of dendrimer leads to phase mixing of soft segment and hard
segment. A point of intersection shows at about 25° C. It is
learned through the control group (0.5G diol+MDI) that this is the glass
transition temperature of the pure hard segment. Furthermore, an
endothermic peak shows at 75° C. due to increasing content of
phase mixing of soft segment and hard segment that results in change of
crystal type of soft segment. Thus the temperature jumps to 75° C.
For D1 series, along with increasing of the hard segment amount, glass
transition temperature (Tg) of the soft segment increases from
-45° C. to -31° C. The melting point of the soft segment is
30° C. The differences between D1 and other series is in that
crystallization peak is almost disappeared. It is speculated side chain
dendritic group increased along with increasing of generations. The soft
segment is difficult to stacked dye to steric hindrance. Furthermore,
glass transition temperature of pure hard segment synthesis by 1.5G
diol+MDI is 50° C. It is found that the glass transition
temperature of pure hard segment is increased along with increasing of
generations.

[0097]In order to test shape-memory property, a rectangular sample (3
cm×1 cm) is cut and is deformed at ninety degrees at Tm (60°
C.) of the soft segment. After deformation, the shape is fixed at
temperature lower than Tg. Then the mold is taken off. Observe recovery
angle respectively at room temperature (25° C.) and 60° C.
and calculate the recovery rate by this angle. But when the hard segment
amount is lower than 35% of the L-series and D0 (C10) series, the test
sample is melt into flow state and is unable to do any tests. The
possible reason is due to lack of physical crosslinking of the hard
segment, and earlier degradation of hydrogen bonding as well as Van der
Walls' Force.

[0098]In order to improve defects of the material, chain extender of
original Decyl Alcohol (C10H21OH) is replaced by Dendritic diol
with an end-group of 1-Octadecanol(C18H37OH) so as to increase
amount of hard segment up to over 45% for increasing temperature range of
the material being applied. Refer to list 3 and FIG. 21, the result shows
that recovery rate of the L-series ranged from 82%˜85%, not
increasing along with the amount of hard segment. In list 3, a represents
side chain dendritic polyurethane with C18 chain. As to D0 series (C18),
the recovery rate is highly as 90%˜92%. As to D1 series (C18), the
recovery rate is getting higher to 97%˜100% and the recovery rate
is increased along with the increasing amount of hard segment. It is
learned that along with introduction of dendrimer, the recovery effect of
the material is dramatically improved. Moreover, along with development
of new-generation dendrimer, the recovery effect is further enhanced. The
main reason of such enhanced recovery effect is due to increased physical
crosslinking caused by strong hydrogen bonding and Van der Walls' Force
in dendrimer.

[0099]Mechanical properties are analyzed by a universal tensile tester
according to stress/strain conditions in ASTM D638 with 100 mm/min
tensile speed, as shown in FIG. 22A, FIG. 22B & FIG. 22c. As to L-series,
the maximum break elongation rate achieves 387%, not related to amount of
hard segment while the tensile strength is increased along with
increasing of amount of hard segment and the L-55 is the best with
tensile strength of 12.7 Mpa. For the D0 series (C18), both break
elongation rate and tensile strength are not significantly increased.
While in D1 series (C18), the maximum break elongation rate achieves 700%
and the tensile strength is increased along with increasing of amount of
hard segment. The tensile strength of D1-50 is 18.8 Mpa. Therefore, along
with increasing of generations of dendrimer, molecular interactions such
as hydrogen bonding and Van der Walls' Force are increased and the
mechanical strength is also enhanced.

[0100]As to yield strength, it also increases along with increasing of the
hard segment. In L-series, the yield strength increases from 8.2 Mpa to
12.4 Mpa. In D0 series (C18), it increased from 5.2 Mpa to 6.1 Mpa. In D1
series (C18), it increases from 3.7 Mpa to 4.4 Mpa. It is learned that
the amount of hard segment also has influence on tensile strength.

[0101]Study atomic structure of crystalline substances by W-XRD (x ray
diffraction), refer to FIG. 23A, FIG. 23B & FIG. 23C. Compared L, D0 and
D1 series with the same position of hard segment, it is found in
L-series, the crystallinity of the soft segment is better when the chain
extender is short-segment DEG. The characteristic peak of
Polycaprolactone is observed at 9.6°, 21.4° and
23.6°. In D0 and D1 series (C18), crystallinity of Caprolactone is
destructed along with introduction of dendrimer and the height of the
characteristic peak is relatively smaller, turning into amorphous state.
Now a bit phase-mixing is occurred due to side chain dendritic structure
in the soft segment. Along with steric hindrance of side chain,
crystallinity of the soft segment is reduced. Although perfect crystal
lattice is not observed in D0 and D1 series (C18), the ductility and
tensile strength are improved with certain degrees by introduction of
dendrimer. By DSC, phase-mixing and molecular interactions such as
hydrogen bonding and Van der Walls' Force induced by dentritic structure
are also observed.

[0102]After introduction of dendrimer with an end group of C10 chain into
the polyurethane, the mechanical properties are not improved
significantly due to lack of physical crosslinking of the hard segment,
and earlier degradation of hydrogen bonding as well as Van der Walls'
Force. Thus the material property is poor when the soft segment is melt.
The shape-memory material between melting point of the soft segment and
glass transition temperature must have good stability. In order to
improve mechanical properties of the dendrimer with an end group of C10
chain, chain extender of original Decyl Alcohol (C10H21OH) is
replaced by Dendritic diol with an end-group of 1-Octadecanol
(C18H37OH).

[0103]The present invention introduces dendrimer into polyurethane. By
control amount of the hard segment, the influence of amount of the hard
segment on the polyurethane is discussed. The chain extender Di(ethylene
glycol with linear structure is used as a control group so as to learn
the effects of dendrimer on polyurethane.

[0104]Through ATR-FTIR and tests of mechanical properties, it is learned
that the hydrogen bonding in the malonamide of dendrimer increases
molecular interactions such as hydrogen bonding and Van der Walls' Force
and the thermal stability as well as mechanical strength of material is
significantly enhanced.

[0105]After introduction of dendrimer, the dendrimer arranges in
polyurethane orderly to form hard domain of the hard segment. This lead
to microscopic phase separation of soft segment and hard segment so that
the recovery rate is improved. In tests of shape recovery, the recovery
rate is up to 90% along with introduction of dendrimer and increasing
generations of dendrimer, some even achieves 100%.

[0106]Additional advantages and modifications will readily occur to those
skilled in the art. Therefore, the invention in its broader aspects is
not limited to the specific details, and representative devices shown and
described herein. Accordingly, various modifications may be made without
departing from the spirit or scope of the general inventive concept as
defined by the appended claims and their equivalents.